I like Prepopulate. I like to have that pseudo-RESTful way of preloading a form to minimize the amount of work a user has to do to get to the point of submitting a form. But I also like clean URLs. This post reviews in detail a technique to use a single prepopulated nodereference field to prepopulate a bunch of other fields based on that reference.
This trick does not use the very fine Prepopulate module at all.
By appending ?gids[]=<group nid> to your node/add URL, you can specify the group audience. By throwing in a comma-delimited list of nids, you can specify multiple audiences. It’s just that simple.
> EDIT: As of Prepopulate 2.0, you cannot directly use hook_form_alter() anyway. See Node Form Dominos to learn about using #after_build to work with Prepopulated values. – 2010/09/09
The Prepopulate module works some great magic to preload forms from URL variables. But suppose you need some extra magic to modify the titles it puts in place?
The Prepopulate module for Drupal is a nifty little tool that resets the default values of forms on their way to the browser. This is particularly useful for crafting links to create nodes with pre-set values. You can even prepopulate Case Tracker form values to help users create cases filled out as you would like.
Bio in Brief: I spend a lot of time thinking about how to build collaboration tools in Drupal. Before that I noodled about with Java looking at long-term data preservation and geospatial data discovery.